1. Field of the Invention
The present disclosure relates to a digital protective relay, and more particularly, to a digital protective relay capable of preventing an erroneous operation according to the influence of noise such as disturbance or harmonic wave.
2. Description of the Related Art
A digital protective relay, as a measuring and relaying device for outputting a control signal of breaking a circuit when various power faults such as overcurrent, short-circuit fault, ground fault, and the like occur on an electrical power line to a circuit breaker to break the circuit, thereby protecting a grid from various power faults, is a device using a microprocessor and capable of implementing a high-performance protective algorithm that has been unable to be implemented in an induction type or static type relay in the related art. Furthermore, the digital protective relay has various additional functions such as a self diagnostic function, a fault recording function, and the like, thereby facilitating a fault analysis as well as providing high reliability. For a circuit configuration example of such a digital protective relay according to the related art, the following patent disclosure disclosed by the applicant of the present disclosure is described below for reference.
(Patent Document 1) KR10-0146088 B1
In order to prevent an erroneous operation according to the influence of noise such as disturbance or harmonic wave in addition to a circuit configuration according to the Patent Document 1, an erroneous sample elimination algorithm may be mounted on a program storage unit (program storage memory) of a microprocessor in a digital protective relay as a program to eliminate noise and extract only aimed measurement signals on an electric power line.